Question: Which of these numbers is composite? ${19,\ 23,\ 67,\ 74,\ 79}$
A composite number is a number that has more than two factors (including 1 and itself). 19, 23, 67, and 79 each have only two factors. The factors of 74 are 1, 2, 37, and 74. Thus, 74 is the composite number.